/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
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 *
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 *
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 *
 *
 *
 *
 *
 *
 *
 */

package javax.accessibility;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;

/**
 * <p>Base class used to maintain a strongly typed enumeration.  This is
 * the superclass of {@link AccessibleState} and {@link AccessibleRole}.
 * <p>The toDisplayString method allows you to obtain the localized string
 * for a locale independent key from a predefined ResourceBundle for the
 * keys defined in this class.  This localized string is intended to be
 * readable by humans.
 *
 * @author Willie Walker
 * @author Peter Korn
 * @author Lynn Monsanto
 * @see AccessibleRole
 * @see AccessibleState
 */
public abstract class AccessibleBundle {

  private static Hashtable table = new Hashtable();
  private final String defaultResourceBundleName
      = "com.sun.accessibility.internal.resources.accessibility";

  /**
   * Construct an {@code AccessibleBundle}.
   */
  public AccessibleBundle() {
  }

  /**
   * The locale independent name of the state.  This is a programmatic
   * name that is not intended to be read by humans.
   *
   * @see #toDisplayString
   */
  protected String key = null;

  /**
   * Obtains the key as a localized string.
   * If a localized string cannot be found for the key, the
   * locale independent key stored in the role will be returned.
   * This method is intended to be used only by subclasses so that they
   * can specify their own resource bundles which contain localized
   * strings for their keys.
   *
   * @param resourceBundleName the name of the resource bundle to use for lookup
   * @param locale the locale for which to obtain a localized string
   * @return a localized String for the key.
   */
  protected String toDisplayString(String resourceBundleName,
      Locale locale) {

    // loads the resource bundle if necessary
    loadResourceBundle(resourceBundleName, locale);

    // returns the localized string
    Object o = table.get(locale);
    if (o != null && o instanceof Hashtable) {
      Hashtable resourceTable = (Hashtable) o;
      o = resourceTable.get(key);

      if (o != null && o instanceof String) {
        return (String) o;
      }
    }
    return key;
  }

  /**
   * Obtains the key as a localized string.
   * If a localized string cannot be found for the key, the
   * locale independent key stored in the role will be returned.
   *
   * @param locale the locale for which to obtain a localized string
   * @return a localized String for the key.
   */
  public String toDisplayString(Locale locale) {
    return toDisplayString(defaultResourceBundleName, locale);
  }

  /**
   * Gets localized string describing the key using the default locale.
   *
   * @return a localized String describing the key for the default locale
   */
  public String toDisplayString() {
    return toDisplayString(Locale.getDefault());
  }

  /**
   * Gets localized string describing the key using the default locale.
   *
   * @return a localized String describing the key using the default locale
   * @see #toDisplayString
   */
  public String toString() {
    return toDisplayString();
  }

  /*
   * Loads the Accessibility resource bundle if necessary.
   */
  private void loadResourceBundle(String resourceBundleName,
      Locale locale) {
    if (!table.contains(locale)) {

      try {
        Hashtable resourceTable = new Hashtable();

        ResourceBundle bundle = ResourceBundle.getBundle(resourceBundleName, locale);

        Enumeration iter = bundle.getKeys();
        while (iter.hasMoreElements()) {
          String key = (String) iter.nextElement();
          resourceTable.put(key, bundle.getObject(key));
        }

        table.put(locale, resourceTable);
      } catch (MissingResourceException e) {
        System.err.println("loadResourceBundle: " + e);
        // Just return so toDisplayString() returns the
        // non-localized key.
        return;
      }
    }
  }

}
